The animal resources diagnostic laboratory was established to serve research animal facilities at the University of Oklahoma Health Sciences Center, the Oklahoma Medical Research Foundation, the Oklahoma City Veterans Administration Hospital and the University of Oklahoma Norman campus. The principal investigator and the co-investigators serve the four institutions as either the director of animal research facilities or as a veterinary medical consultant. A close association therefore exists between the diagnostic laboratory and the animal health programs at these institutions. The animal health programs benefit through improved capability for detecting, diagnosing, treating and preventing disease in the animal colonies. Procedures employed include necropsy, histopathol gy, serol gy, hematol gy, microbiol gy, parasitol gy, urinalysis and clinical chemistry. The diagnostic laboratory has been useful in developing new or improved animal models for biomedical research. Information provided during the early phases of investigation have guided investigators in refinements of experimental techniques. The institutions also benefit from the collection of case materials which are used in providing training in laboratory animal and comparative pathology.